73 Cj5 1-wire Altenator Swap

Hi.
I have a '73 CJ5, 258, 4sp with either a bad alternator or regulator. I'd like to swap them for a 1 wire alternator. What alternator, 37A or so, will bolt up? The BBB 7427 listed on Rock Auto uses an external regulator.
Thanks.

 

I got one on E Bay for a Tractor, it has the wider pully on it for the factory fan belt, I think it's 60 amp.

 

The problem with many car alternators is they do not charge at low enough rpm. This may or may not be a problem depending on how you use the Jeep. Most of the time I am driving my Jeeps at low speed, seldom drive them on the road at higher speeds, so I wanted an alternator that would charge while putting around the farm or crawling around on trails.

After being unsatisfied with two alternators I bought from Rock Auto I finally bought one from Classic Military. Costs a little more, but charges at low RPM, and has the correct pulley for a Jeep.

I have a volt meter on my dashboard and this alternator produces a charge at idle. It has been on the Jeep for about a year, and I am very pleased with it.

https://jeep1942.com/?page_id=10673

 

Thanks Oldpappy. I never thought of the rpm required to charge. I don't do a lot of idling around in the bush, but that's what I like the most about this jeep, it'll lug forever. That is a pricey little sucker for sure.

 

Oldpappy's choice of alternator is good. It is a one wire 10SI deco with a small diameter pull to turn it fast. This alternator will start charging at an even lower RPM if you buy the plug for it and wire it to an accessories terminal but that is not necessary.

 

You can buy that same alternator on Amazon for $80. Search for "10SI self exciting alternator". I doubt if you will need the wide pull that Oldpappy is using since you have a 1973 with a 258 in it.

 

Do you have the Wilson part number off that alternator? I can take that to my local NAPA and see if they can get it, or match something up. Shipping to Canada for that will be crazy I'm sure.

 

I installed a tuff stuff one wire alternator on my 198 odd fire. Puts out charging voltage even at idle and works great. They’re typically between $100 and $150 on Amazon depending on the model.

 

No, I don't need the wide pully. I think I found it on the Canadian Amazon site. https://www.amazon.ca/ALTERNATOR-TR...rds=7127se&qid=1693617558&s=automotive&sr=1-3 I won't be buying that, even if it was the right pully, There's a made in China one too for $120.00. I'll be staying away from that one too.

 

I mounted a one wire on a stock Motorola bracket by just cutting the stock mounting bracket on the alternator back about an inch to line it up with the front pully on the motor. It's been on there since 07, I have to gas it up to start the alternator charging, but then it charges at idle, no problem. Good Luck.

 

I run a 100 amp 1 wire from Summit, I don't recall having to modify anything to make it fit. Been on there over a decade, works fine. You'll want to upgrade the heavy charge wire coming off the back of the alternator.
Summit Racing SUM-810340 Summit Racing™ Alternators | Summit Racing

 

Thanks for all the suggestions. I did try a '76 alternator. I had to make a bracket because the fan is larger and wouldn't fit in the existing bracket. Then, it was too far back. The pulley sits about 1/4" further back than the '73 alternator, so I could either modify the bracket or look for an offset pulley.. if they even exist. I didn't want to spend time doing that so I ordered the '73 alternator and a new regulator. They are installed and working fine.

 

Hello and thanks for taking time to read this.

Now that the 1970 CJ5/Dauntless project is completed, I've been driving it more and it appears I have a charging issue. The Walck's wiring harness paperwork showed two alternator options, since the Jeep has no stereo or other auxiliaries I bought a new 37amp alternator. I'm having to put the battery on a charger if I drive it much. The battery checks good, but with engine idling, I'm only getting a little over 12.5 volts at the battery. I've checked the wiring, have replaced the voltage regulator with no improvement even tried another 37amp alternator. Is it possible I'm not putting enough amps back in the battery and need to step up to higher output alternator?

Having read this thread, should I fit the 100amp one wire ( heavier gage ) from the alternator output to the battery post on the starter, isolate and seal the Walck's harness alternator wires as a solution?

Thank you!

 

Sounds like something wrong with the wiring. If I had to venture a guess, i would check the exciter wire. Other culprit could be too small of a wire going from alternator to the battery.

this sounds like a very similar problem to what I was having. I went with a one wire alternator and never looked back.

 

Thanks boopiejones, what did you do with the un-used wires after you went with one wire ( larger )?

Again, thank you for your reply!

 

You can just leave them if you want. Just make sure they can't short on anything. It's a lot more sanitary to just remove them. As above, make sure the gauge of the output wire matches the potential amperage of the alternator.

I don't really agree with the posts stating alternator output is "low" at low rpms. Most of them will far exceed a generator well below 1000 rpms. I have used the one wire 10SI's on several tractors with excellent results. Those are outputting 30 to 40 amps at idle. No doubt some of that output performance is based on pulley size but with the tractors I'm just using the stock GM 2 groove pulley with the center machined out for the wide belts used on the Case 700 series diesels.

 

I got this AC Delco from Rock Auto to replace the original. I also was not getting 14.4+ volts at idle (only 12.6v)
It’s the exciter wire, like boopiejones mentioned. once I had the exciter wire hooked back up properly (so you don’t have alternator feedback) I am getting 14.8v at idle.

 

Thanks again boopiejones, Bech66Bum, do you have a picture of the rear of your alternator showing how you have it wired/hooked up?

Thanks you!

 

I think I do, have to find it!

This pic shows the red wire from alternator to the starter main post.

 

Thanks Beach66Bum, that's how I have my starter wired. From what you and those who have replied to my question have said, it sounds like I do not have the wire from the voltage regulator attached to the correct post on the alternator. If you have a picture that confirms where that should be attached please post it!

THANK you!